双层旋转锥形液膜一次破碎特性数值研究

为了全面加深对锥形液膜一次破碎机理的认识，对双层锥形液膜的雾化过程进行了数值模拟，重点研究了压降和同轴旋转空气对双层液膜宏观形态、液膜破碎模式、液膜破碎长度和喷雾锥角等液膜一次破碎特性的影响。数值计算的喷雾场宏观形态与试验结果接近，喷雾锥角和索特尔平均直径的计算最大误差分别为4.9%、7.4%。研究表明：同轴旋转空气参与雾化会改变喷雾场的整体形态；增大压降和空气速度会改变液膜的破碎模式和主导表面波模式；双层液膜的合并会在液膜表面产生剧烈的表面波动，同时会略微增大液膜的喷雾锥角；液膜的破碎长度会随着压降和同轴旋转空气轴向速度的增大而减小。该研究有助于进一步研究双层液膜一次破碎的机理，从而指导对双路离心式喷嘴的雾化认识。

Numerical study on primary breakup characteristics of dual-layer rotating conical liquid sheets

To comprehensively deepen the understanding of the primary breakup mechanism of conical liquid sheets, this study numerically simulated the atomization process of dual-layer conical liquid sheets, focusing on the effects of pressure drop and coaxial rotating air on the primary breakup characteristics of the liquid sheet such as the macroscopic morphology of the dual-layer liquid sheet, the breakup mode and length of the liquid sheet, and the spray cone angle. The macroscopic morphology of the numerically calculated spray field was close to the experimental results, and the maximum errors of the numerically calculated spray cone angle and the Sauter mean diameter were 4.9% and 7.4%, respectively. The numerical results show that the participation of coaxially rotating air in the atomization will change the overall morphology of the spray field. With the increase of pressure drop and air velocity, the breakup mode and the dominant surface wave mode of the liquid sheet will be changed. The merging of the dual-layer of liquid sheets will produce drastic surface fluctuation on the surface of the liquid sheet, slightly increasing the spray angle. The breakup length of the liquid sheet decreases as the pressure drop and the axial velocity of the coaxially rotating air increase. This research facilitates further studies on the mechanisms of dual-layer liquid sheet primary breakup, thus providing guidance in the understanding of atomization in the double pressure swirl injector.